Blindstitch sewing machine with eccentric mounting for work support



Aug. 13, 1963 T. D. TAYLOR 6 BLINDSTITCH SEWING MACHINE WITH ECCENTRICMOUNTING FOR WORK SUPPORT l0 Sheets-Sheet 1 Filed March 13, 1961 3, 1963T D TAYLOR 3,100,468

E WITH ECCENTRIC BLINDSTITCH sEw'ING' MACHIN MOUNTING FOR WORK SUPPORTFiled March 13, 1961 10 Sheets-Sheet 2 Aug. 13, 1963 T. D. TAYLORBLINDSTITCH SEWING MACHINE WITH ECCENTRIC MOUNTING FOR WORK SUPPORT 1OSheets-Sheet 3 Filed March 13, 1961.

Aug 1963 D TAYLOR 3,100,468

T. BLINDSTITCH SEWING MACHINE WITH ECCENTRIC Filed March 15, 1961MOUNTING FOR WORK SUPPORT l0 Sheets-Sheet 4 Aug. 13, 1963 T. D. TAYLOR3,100,468

BLINDSTITCH SEWING MACHINE WITH ECCENTRIC MOUNTING FOR WORK SUPPORTFiled March 15, 1961 10 Sheets-Sheet 5 Aug. 13, 1963 T. D. TAYLOR3,100,468

BLIND-STITCH SEWING MACHINE WITH ECCENTRIC MOUNTING FOR WORK SUPPORTFiled March 13, 1961 10 Sheets-Sheet 6 I nu Aug. 13, 1963 T. D. TAYLOR3,100,468 BLINDSTITCH SEWING MACHINE WITH ECCENTRIC MOUNTING FOR WORKSUPPORT Filed March 15, 1961 10 Sheets-Sheet 7 '7 Aug. 13,1963

T. D. TAYLOR 3,100,468 BLINDSTITCH SEWING MACHINE WITH ECCENTRICMOUNTING FOR WORK SUPPORT Filed March 13, 1961 10 Sheets-Sheet s Aug.13, 1963 T. D. TAYLOR 3,100,468 BLINDSTITCH SEWING MACHINE WITHECCENTRIC MOUNTING FOR WORK SUPPORT Filed March 15, 1961 10 Sheets-Sheet9 Aug. 13., 1963 T. D. TAYLOR 3,100,468 BLINDSTITCH SEWING MACHINE WITHECCENTRIC MOUNTING FOR WORK SUPPORT Filed March 13, 1961 10 Sheets-Sheet10 89d say PIC-3.22.

United dtates Patent @fiice 3,100,468 BLINDSTITCH SEWING MACHINE WITHEiCCEN- TRIC MOUNTING FUR WORK SUPPORT Thomas D. Taylor, deceased, lateof Hermann, M0., by Georgia Brueggenjohann, executrir, Hermann, Mo.,assignor to Union Special Machine Company, Chicago, 111., a corporationof Illinois Filed Mar. 13, 1%1, Ser. No. 95,441 17 Claims. (Cl. 112-173)This invention relates to a blindstitch sewing machine and moreparticularly to a novel combination of features involved in the pivotedwork apron or support, which carries a node former, and mechanism forrocking the work support during the operation of the machine to form a 2to 1 or skip type stitch or for eliminating such rocking whenever a 1 to1 or non-skip type stitch is desired. Simple and reliable means,requiring a minimum of effort on the part of the operator, is alsoprovided for rocking the work support in response to the operation of aknee press or the like. This latter means is such as to provide maximumfreedom to the operator in the introduction and removal of work and alsosuch as to permit the work support to rock downwardly in the course ofoperation of the macihne in forming a skip type stitch and in thefeeding of extra thicknesses of Work, such as cross seams, through thestitch forming Zone. Coupled with the foregoing, in a unique manner, isa thread nipper mechanism which is normally inactive but is renderedelfective upon lowering of the work support by the knee press member soas to facilitate breaking of the thread over the looper element as astitched work piece is removed from the machine.

It has been a primary object of the invention to provide anexceptionally compact and sturdy construction for achieving theforegoing purposes, and one which may be very simply and accuratelyadjusted and is reliable in its operation. A further object has been theproduction of a machine of the foregoing character which is capable ofoperation at high speeds.

A feature of the invention is the mounting of the Work apron or support,which is adapted for rocking movements by connections from the mainshaft of the sewing machine to produce skip stitches, on pivots adjacentthe rear end of the work support. While work aprons or supports haveheretofore been mounted on pivots at the rear end of the support, it hasbeen considered necessary, prior to the present invention, to provideforward pivots for work supports which are rocked automatically from themain drive shaft of the machine to produce skip stitches. In accordancewith the present invention, the great advantage of rear pivots, inproviding substantial clearance between the work support and the fixedpresser foot for the insertion and removal of work, has been achieved ina machine having a node former mounted on a shaft carried by the Worksupport so as to make possible the selective formation of skip stitchesby the automatic rocking of the work support or non-skip stitches byeliminating such rocking of the work support. Moreover, the constructionprovided by the invention is such that the work support is given acompound movement upon the operation of the knee press. It is given adownward and slightly forward movement at its pivotal support, by virtueof an eccentric mounting of the pivot on the frame of the machine, andit is rocked downwardly about its pivot to give the forward end asubstantial further downward movement. This greatly increases the spacebetween the entire work support and the presser foot as the knee pressis operated. A special toggle linkage is provided adjacent the forwardend of the work support to bring about this compound movement, and aspring is provided for restoring the parts quickly and accurately totheir normal positions upon release of pressure on the knee press.

Patented Aug. 13, 1963 Another feature of the invention is the provisionof a very simple and reliable mechanism, capable of quick adjustment, topredetermine whether the work support will be held stationary duringsuccessive cycles of operation of the machine or will be rocked duringcertain cycles to provide a skip stitch. This mechanism involves aneccentric control disk arranged to be driven at a half or a third orsimilar fraction of the angular speed of the main drive shaft. Adjacentthis control disk is another disk mounted to turn about the same shaftwhich carries the control disk and provided with a concentric peripheralsurface of a radius equal to the major radial distance of the peripheryof the control disk. This second mentioned disk has a depression in itsperiphery which may be shifted into and out of a position to cooperatewith a roller which ext-ends across at least a partof the periphery ofboth disks. By simply shifting a lever or the like,rto predetermine thelocation of the depression of the concentric disk, the machine may beset to produce either skip stitches or non-skip stitches. The rollermentioned is connected with a rock member which is in turn connectedwith the toggle linkage discussed above to bring about a slight rockingmovement of the work support during predetermined cycles of the machinewhen a skip stitch has been selected. Readily adjustable means is alsoprovided for shifting the pivotal axis of the rock member to accuratelyadjust the depth of penetration of the needle of the machine into thenode of the work being stitched. By depth of penetration is meant thedistance below the top of a node formed in the work that the needlepasses through such node.

A'further special feature of the invention is the provision of a simpleconnection from the shaft about which the work support is rocked tobring about automatic operation of the thread nipper mechanism'mentioned, whenever the work support is moved downwardly by the kneepress for insertion or removal of work.

Still another feature of the invention is the provision of simple,effective and reliable mechanism for constantly swinging the node formerthrough the same arcuate path, regardless of whether the machine is setfor the production of skip stitches or non-skip stitches. Thedetermination of the type of stitching to be produced, skip or non-skip,is left entirely to the rocking or non-rocking of the work support inthe course of operation of the machine.

A still further feature of the invention is the provision of a togglemechanism for retaining the work support in a desired position. Thistoggle mechanism is such that the work support may be easily andreliably shifted to accommodate different thicknesses of work, toproduce skip stitches, and to lower the work support for the insertionand removal of work, but is quickly restored by spring means to itsnormal position after downward movement for any of the purposesspecified.

An additional feature of the invention has been to provide a quickly andreadily adjustable means for predetermining the normal position of thework support and the particular are through which the work support isrocked in the course of forming skip stitches. This feature is closelyrelated to the proper positioning of the node or ridge former in theproduction of skip and non kip stitches. r

Other objects, features and advantages of the invention will appear fromthe following detailed description of an illustrative embodiment of thesame which will now be given in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a view, partly in planand partly in horizontal section, of asewing machine embodying the invention, the work support or apron beingomitted;

FIG. 2 is a plan view of a portion of the sewing machine showing thework support and adjacent portions of the frame structure;

FIG. 3 is a vertical sectional view through the machine taken along theline 33 of FIG. 1;

FIG. 4 is a front elevational view of a part carried by the worksupport, with a portion of the forwardly extending arm of the main frameshown in section; 7

' chine taken along the line 7-7 of FIG. 1;

FIG. 8 is a vertical sectional view of certain parts taken along theline 8-8 of FIG.

FIG. 9 is a perspective view of an element shown in FIG. .8;

FIG. 10 is aventical sectional view through a portion of the machinetaken along the line 10-10 of FIG. 1;

FIG. 11 is a ventical sectional view taken transversely through the worksupportand the adjacent portion of the frame of the machine along theline 11-11 of FIG. 1;

FIG. 12 is a detail view of certain partsshown in FIG. 11;

FIG. 13 is a bottom view of the right hand portion of the frame of themachine shown in FIG. 1;

'FIG. 14 is a ventical sectional view taken along the line 14.14 of FIG.1 and shows a nipper mechanism embodied in the machine;

- FIG. 15 is a perspective view of a bracket member shown in FIG. 14;

FIG. 16 is a perspective view of a pivoted member carried by the bracketshown in FIG. 15;

.FIG. 17 is a bottom plan view of a plate member provided at the top ofthe frame;

FIG. 18 is a perspective view showing a portion of a Lewis 150 typemachine. This is adapted to form a single thread blindstitch, but itshould be understood that the present invention could be applied to amachine adapted to produce a two thread blindstitch, of either thechainstitch or lcckstitch types.

The mechanism for operating the stitch forming devices, includingacurved needle and a recipnocatory and oscillatory loo-per, and also foroperating a top feed dog, will now' be briefly described. 'Adjacent theleft'end of the main shaft 15 of the machine there is secured thereto aspherical eccentric 17 (FIG. 1) at the rear end offthe arm 12. Thiseccentric cooperates with a strap 18 connected with a pi-tman whoseopposite end is pivotaily connected with an arm (not shown) secured to ashaft 1 9 suitably journaled in the frame arm 12 (FIG. 3). At theforward end of shaft 19 there is secured an arm 20 which carries acurved needle 21. It will be understood that through the connectionsdescribed the needle will be reciprooated along an arcuate path tion27of a crank 28 secured to the shaft 15. Intermedithe work support andcertain mechanism connected therei with for positioning and controllingthe movement of shown in FIG. 2.2,taken along the line 23-23- of thelatter. i

Referring now to the drawings, the illustrative machine comprises a mainframe having a base portion 10 (FIGS. 1, 2, 3 and 7) having, at its rearpart, an upstanding portion 11 which carries, at its upper end, an arm11a that projects toward the left (FIG. 1) and has secured thereto, atits left end, a forwardly extending arm 12. Mounted [for rockingmovement upon the portic-n1 10 of the frame is a work support or apron13 (FIG. 2) having anextension 14 to which is secured a frame member 14apositioned beneath the forward end of the arm 12. A main'rotary driveshaft 15 is suitably journaled in the portion 11 and arm 11a of theframe, this shaft extending outwardly of the frame at its right end(FIG. 1) and having secured thereto a combined handwheel and prulley 16through which the machine may be operated. .It will beunderstood thatthe pulley may suitably be connected by a belt to an appropriate powersounce such as an electric motor and clutch unit of conventionalconstruction.

The blindstitch sewing machine to which the present invention may beappied may be of any suitable type, but the invention has beenillustrated in connection with ate its length, the rod 23 is supportedfor turning and swinging movements in the manner disclosed in the patentto Mueller, No. 2,5 88,274, gnanted March 4, 1952. As will be .clearfrom that patent, the arrangement is such that the looper 22 is given \acompound movement swinging movements from one side to the other of thenode former, to be described. In the course of such oscillatory orswinging movement of fingers of the looper are turned through an angleof about 90".

For advancing the work in the course of stitch formation a top feed dog29 (FIG. 1) is provided. This feed dog is secured to a feed bar 30extending longitudinally of the arm12 and having a strap 31 surroundingan eccentric 32 secured to the main drive shaft 15. Eccentric 32 may beof the adjustable type to enable variation in the extent of the feedstroke imparted to the feed dog during each cycle of the machine.Intermediate its ends the feed bar 30 is supported for rocking andlongitudinal movement by a member 30a. The arrangement for this purposemay. be of the character disclosed in the patent to Mueller, No.2,109,014, granted February 22, 1938. As will be understood, the feeddog 29' is moved through an elliptical path by the operation of theeccentric 32.

.It is thus lowered into engagement with the work, then is urgedupwardly against the underside of a fixed presser foot 33 which has anopening therethrough for the passage of the feed dog 29.

As best shown in FIGS. 4, 5 and 6, the means for urging the workupwardly against the undersurface of the presser foot 33 and against thefeed dog, when the latter is imparting its feed movement to the work,comprises a pair of platens 34 and 35 which are disposed at oppositesides of the node former to be described. The two platens are mounted ina similar way, the mounting of. the platen 34 being most clearly shownin FIGS. 5 and 6.. It is rockably mounted at the upper end of an arm '36pivotally connected by a screw stud 37 to the member 14a of the frame. Aspring 38, connected at one end with a screw member carried by the framemember 1411 and at its other end with a downwardly extending projectionfrom the arm 36 serves to urge the latter in a clockwise direction andto thus urge the platen 34 against the presser foot 33. The two platensare forced downwardly against the action of the springs as the work isadvanced along the undersur-face of the presser foot 33. When the worksupport 14 and its extension 14a are rocked downwardly upon theoperation of a knee press, in the manner to be explained, a projection39 of the arm 36 is urged by the spring 38 into engagement with theupper edge of a plate 40 secured to the frame member 14a. This preventsundue rocking 0f the arm 36 which carries the platen 34. As stated, thesame arrangement is provided for the platen 35. p 1

Turning now to the mounting of the work support on the frame of themachine, the portion 13 of the work support is provided with rearwardlyextending bearing portions 41, 42 and 43 (FIG. 2) which cooperate with ashaft 44 to permit rocking movement of the work support about the axisof that shaft. Shaft 44 is supported at its two ends eccentrically ofthe axis of the shaft. Thus, at the left end a pointed pivot screw 45,having threaded engagement with a lug 46 of the frame member 18,cooperates with a conical recess 45a in the left end of shaft 44 (FIGS.1, 2. and 7) which is disposed eccentrically to the axis of the shaft.When properly adjusted the screw 45 is retained in set position by a setscrew 47. Similarly, the right end of the shaft 44 is supported by thepointed end of a screw 48 having threaded engagement with a lug 49 ofthe frame It}. The pointed end of this screw cooperates with a conicalrecess 48a in the right end of the shaft 44 which is axially alined withthe recess 45a in which the pointed end of screw 45 is inserted. Screw48 is retained in adjusted position by a set screw 58 (FIG. 2). Theshaft 44 is caused to turn through a suitable angle under certainconditions about the eccentrically disposed pivot screws 45 and 48. Whenit is so turned it tends to bring about slight lifting and loweringmovements of the pivoted portion of the work support. As will beexplained, it is turned in a direction to cause lowering of the pivotedportion of the work support in response to operation of a knee press andit is turned in the opposite direction by a spring.

Forwardly of the shaft 44 the work support 13 is held in its normalposition, shown in FIG. 7, by a toggle linkage. This includes a member51, shown in detail in FIG. 21, which is pivotally mounted on a rod orpin 52. It also includes a member 53, shown in detail in FIG. 20, whichis pivotally mounted upon a pin or screw stud 54 carried by a downwardlyextending lug 13a of the work support 13. Member 51 has an outwardlyextending bearing element 55 adapted to fit between bearing lugs 53a onthe member 53. A pin 56 which is passed through the bearing lugs 55 and53a serves to pivotally interconnect the two members 51 and 53. Alsopivotally mounted on the pin 56 is the end of a bar 57 having a forkedportion 57a which straddles the lugs 53a and has an opening in each armof the fork surrounding the pin 56. At its opposite end the bar 57 ispivotally connected by a pin 58 with a portion of a projection 59 whichextends downwardly at an angle from a collar 60 secured to the shaft 44(FIGS. 2, 7). As indicated in FIG. 1, the collar 68 is provided with agroove extending around a portion of its circumference to accommodatethe bar 57. The collar is secured to the shaft 44 by a set screw 68::(FIG. 2).

Also secured to the shaft 44 at some distance from the collar 69 isanother collar 61 having a set screw 61a to lock it to the shaft (FIGS.1, 2 and 14). Connected with the collar 61, at a point below and at oneside of the axis of the shaft 44, by means of a screw 62 is a link 62ato the outer end of which is connected a spring 63 The opposite end ofthe latter is connected with a screw stud 64 carried by the main frameof the machine and linkage is limited by the engagement of a shoulder 65on member 53 with a shoulder 65a on member 51.

Toggle member 51 is pivotally connected by the pin 52 with an arm 66 ofa rock member which is shown in detail in FIG. 19. Its general relationto other parts is shownin FIG. 7. A long cylindrical hub portion 66a ofthe rock member is secured by set screws 66b to a shaft 67 rockablymounted in the frame of the machine. In the plane of the arm 66, but atthe opposite side of the axis of the shaft 67, is a downwardly extendingarm 68. This carries a screw member 69 to which is attached one end of aspring 70, the opposite end of which is connected to a screw stud 71adjustably carried by the frame of the machine. An arm 72 extendingdownwardly from the opposite end of the sleeve 66a has pivotallyconnected therewith a link 73, this being connected to arm 72 by meansof a pivot pin 72a. Link 73 is connected with a block 75 by a screwmember 74 provided with nuts for varying the position of the block 75 inrelation to link 73 and thus varying the effective length of the .link.Block 75 has trunnions 76 extending outwardly from its opposite sidesand providing bearing means for the forked lower end of an L-shapedlever 77. The latter is connected by a pivot pin 78 with a flattenedportion of a cylinder 79 adjustably mounted in an opening in the mainframe of the machine. Adjacent the right end of the lever 77 (FIG. 7)there is rotatably mounted thereon a roller 80, the latter beingjournaled upon a screw threaded pivot pin 80a. Roller 80 is adapted tocooperate with the periphery of two disk-like members 81 and 82 whichare mounted in side by side relation upon a shaft 83 (FIGS. 7-10,inclusive). Member 81 has a major portion of its periphery ofcylindrical form, concentric with the axis of the shaft 83, but it isprovided with a depression or indentartion 81a in one region of itsperiphery. A sector-like recess 81b is provided in the periphery of disk81 at the opposite side of the shaft 83 and a pin 84 extends across thisrecess. This pin cooperates wtih a notch in the lower end of a lever 85which is rockably mounted on the main drive shaft 15 of the machine.Lever 85 extends upwardly through an opening 85a in a closure plate 85bsecured to the top of portion 11 of the frame (FIGS. 10 and 17). Amember 85c secured to the underside of the plate 85b serves to retainthe lever 85 in either of the two positions into which it may beshifted. A spring 85d serves to urge the lever 85 toward the right (FIG.10) at one side or the other of the member 850 to retain the lever inits set position. An opening 85a in the plate 85b permits theintroduction of lubricant to certain parts of the mechanism.

A gear 86 secured to the shaft 15 meshes with a larger gear 87 rotatableon the shaft 83. If the machine is intended to provide a two to one typeof skip stitch when desired, the gear 87 will be given one revolutionfor each two revolutions of the gear 86. Should a three to one type ofskip stitch be desired, the gears 86 and 87 should be such as to bringabout one revolution of the latter for three revolutions of the gear 86.Disk member 82 is secured to the gear 87 and therefore rotates with thelatter. The disk 82 is mounted on gear 87 slightly eccentrically inrelation to the axis of the latter and of the shaft 83, so that in thecourse of its rotation it tends to force the roller 80 downwardly onceupon each two revolutions of the main shaft. However, this is done onlywhen the depression 81a of disk 81 is positioned directly over theroller 80. Disk 81 may be brought into such a position by moving thelever arm 85 (FIG. 8) toward the left so as to cause a limited clockwiserotation of the disk 81. When the latter is in the position shown inFIG. 8 its cylindrical surface will retain the disk 80 in a fixedvertical position and will not permit the latter to rise as the portion:of the periphery of disk 82 which is of less distance from the axis ofthe shaft 83 is positioned over the disk 80. Thus, by a simple turningof the member 81 the machine may be set for either a 1 to l, non-skipstitch, 'or a skip type stitch. In this connection it should be notedthat upwardmovement of the roller 80 (FIG. 7) serves to rock the arm 72,shaft 67 and arm 66 in a counterclockwise direction. Such rockingmovement, it will be understood, is brought about by the spring 70 whenthe machine is adjusted for a skip type stitch and the low portion ofthe eccentric disk 82 is brought into engagement with the roller 80. Theresulting downward rocking of the arm 66 will carry the toggle link 51slightly downwardly and this in turn will draw the toggle link 53,.andhence the work support 13;, slightly downwardly. The extent of suchdownward movement of the work support is just suflicient to permit-askip stitch to be formed. Shoulders 65 and 65a on the toggle links willbe separated slightly at this time.

Very simple means is provided for varying the depth of penetration ofthe curved needle through a node formed in the work. For this purposethe member 79 may be adjusted axially to a limited extent by means of ascrew thneaded member 88 (FIG. 7) cooperating with internal.

threads in an opening within the cylindrical portion of member 79.Member 88 carries at'its upper end a knob 89 (see also FIGS. 22 and 23)which is secured to the shank of'member 83 by a set screw 99. The knob89 is provided with a conical skirt portion 89a carrying suitableindicia to show its setting. Skirt 8% is arranged to turn within arecess provided in the top of a plate 91 secured in any suitable way tothe main frame of the machine. Member 88 has a collar 88!; above thescrew threaded portion of the member and has a. cylindrical stem 88aabove the collar. On this stem there are mounted two washers 88c and 88dbetween which is positioned a ball bearing assembly 88a. As best shownin FIG. 7, the washer 88c rests upon the collar 88b while the washer 38dengages the undersurface of the member 91. The latter is provided with anotch 91a adapted to cooperate with the indicia on the shoulder 89a toshow the particular setting of the parts; Screws 911!) may be employedfor securing the plate 91 to the frame of the machine. Washers 89b and890, (FIGS. 22 and 23) retaining between them another ball bearing unit,are mounted on the stem 88a above the upper surface of member. 91. Aspring urged ball 89d carried by the knob 89 cooperates with spaceddepressions 910 in the upper surface of member 91 to retain the knob andthe screw member 88 inwhatever position they may be set. Preferably theknob 89 is limited to one. revolution in relation to the member 91 andthis is brought about by 'a-downwardly extending stem of a screw 89scarried by the knob arranged to cooperate with an upwardly extendingscrew jhld (FIG. 7)

, which is in the path of movement of screw 896.

It will be appreciated that when the knob 89 is turned in a direction toshift the member 79 downwardly, the pivot 73 for the lever 77 will bemoved downwardly about the axis of the roller 89. This causes a slightmovement of the trunnions 76 toward the right (PEG. 7) and hence a.slight counterclockwise movement of the shaft 67 with the result thatthe work support 13 is lowered slightly. This will correspondinglyreduce the depth below the'top of the node of the work at which thecurved needle passes through such node. Turning of the knob 89 in theopposite direction will bring about the opposite result.

Means are provided for enabling the operator to bring about down-wardmovement of the Work support at will, with a minimum of etfort. For thispurpose there is shown a knee press member (FIG. 1) connected with abent rod 93'h aving an upwardly, then forwardly, the-n upwardly, thenlaterally and then rearwardly extending portions. The rearwardlyextending portion of the rod is connected by a coupling member 94 with ashaft 95 journaled in the base portion of the frame of the machine. Acollar 96 secured to shaft 95 retain-s it against outwardmovement whilethe coupling 94 retains it against inward movement. Atthe inner end ofthe shaft there is a screw stud 102; The roller 101 is normally spaced aslightdistance below an arm 1%3 integual'wi-th the toggle member 51. itwill turn the shaft -99 through a suitable angle and will cause the arm10b to rock in a clockwise direction (FIG. 18). At this time the roller101 will engage the arm 103 and will cause the toggle member 51 to rockcounterclockwise about the pivot 5-2. It will be understood that thiswill also cause the toggle member 53 to swing outwardly, or clockwise,and by virtue of the link 57 connected with collar 60 it will causerocking of the shaft 44 in a clockwise direction. Such rocking of theshaft 44 will be resisted by the spring 63 which will serve to restorethe parts to their normal position when the force is removed from theknee press. To limit the extent of rocking of the shafts 99 and44,through the operation of the knee press, an adjustable screw 1% ismounted in the arm 199 and is adapted to engage the surface of the hubportion 664; of the rock member 66 etc. shown in FIG. 19, which at thistime will be in a predetermined position.

To insure having the roller 161 norm-ally located a slight distancebelow the arm 193, so that the latter will not engage the roller due toslight lowering of the work 7 has one end connected with the pin 99aandits other end with a pin 99c extending inwardly from the trame of themachine. Adjacent the opposite end of the shaft 99 there is secured acollar 99:! carrying a screw element 3% which cooperates with a pin 99carried by the frame to limit the extent of rocking of the shaft by thespring 995.

As has been stated, a node former is mounted for rocking or oscillatorymovement in the work support. This is best shown in FIGS. 36, inclusive.It comprises a segment 105, preferably having its upper, circumferentialedge beveled to facilitate its creation of a fold or node in the work atthe time the needle is being passed through the latter. The node former#195 is secured to a shaft 196 journaled in suitable bearing sleeves 1&7and 198 carried by the work support (13, 14, 14a). A collar 1tl9 securedto the shaft 106 is arranged to cooperate with the left end of thebearing sleeve 108 to prevent movement of the shaft toward the right(FIG. 3). An arm .1163 is clamped to the shaft ltldadjacent the oppositeend of bearing sleeve to? and serves to prevent shifting of the shaft166 toward the left. Arm 110 (FIG. 7) has pivotally connected therewith,by means of a screw stud 1-11, a pitman 1-12. of substantially L-shapedconfiguration, the .upper end of this pitman having a strap 113 whichcooperates with an eccentric 114 secured to the shaft 15. it will beapparent that upon each revolution of the shaft 15 the p-itman 112. willimpart a rocking movement to the arm i110 and hence to theshaft 106, andtherefore also to the node former 105. In accordance with the invent onthe node former is given the same extent and path of movement upon eachrevolution of the shaft 15 regardless of whether the machine is set forthe production of skip stitches or non-skip stitches.

For controlling the tension on the needle thread at various times duringthe operation of the machine, there is provided a thread tensioningdevice 115, with provisions for automatic release of tens-ion duringcertain portions of a cycle of the machine, and a thread nipper 116which becomes effective only when the work support is lowered by theknee press to introduce or remove work. It will be understoodthat thethread from a cone, or other suitwhich meshes with a bevel When the kneepress member is actuatedi9 able source of supply, .is passed between thetension applying disks of the unit 116 and then of the unit 115 (FIGS. 3and 10) from which the thread is delivered through suitable guides to.the needle. The thread tensioning device 115 is controlled by a pin 117whose normal position may be adjusted by changing the height of thesleeve through which it extends so that the posit-ion of the lower endof the pin, in its lowermost position, may

be varied slightly and thus alter the duration of the portion of a cycleof the machine during which the tension applied to the thread by thisdevice is released. The lower end of the pin 117 cooperates with aneccentric 118 carried by a sleeve 119 secured to the shaft 15. The

eu'xgmlsr position of the sleeve .119 in relation to the shaft may bevaried by loosening a set screw 11%, then turning these parts inrelation to each other, and then retightening the screw. This willdetermine the portion of a cycle of operation of a machine during whichthe tension is applied to the thread and during which it is releasedfrom the thread. It will be understood that the arrangement is such thatthe upper end of pin r117 engages the bottom of a member which isnormally urged downwardly by a spring 120 into enga ement with theuppermost of the two tension applying disks 121. The eccentric 1131ssuch that during a certain portion of a cycle of the machine the pin 117will be lifted to offset the force of the spring 120 but at otherportions of a cycle the pin will be lowered so that the spring 12% iseffective to apply its tensioning force to the thread.

The thread nipper mechanism 116 has a spring 122 whose force may bevaried by adjustment of a nut 122.1 to apply a nipper force to thethread. The lower end of spring 122 cooperates with a cuplike member 123which is urged by the spring against the uppermost of a pair of threadtension applying disks 124. During the normal operation of the machinethe member 1'23 is held in a slightly elevated position by the upper endof a pin 125 so that no tension will be applied to the thread in itspassage between the disks 124. Pin 125 has a threaded lower portion 125a(FIG. 14) which permits adjustment of the height of the pin in relationto a vertically extending rod 126 to which the pin is attached. At itslower end the rod 126 is pivotally connected with an arm 127 of a membershown in detail in FIG. 16. Member 127 is rockably mounted on a bracket128 (FIG. which is secured to an inclined surface provided on the frameof the machine. A downwardly extending arm 127a of the member 127 has anopening surrounding a rod 129 which carries a collar 130 that isnormally urged in the manner to be explained, against the left face ofthe arm 1270. The upper left end of the rod 129 cooprates with adownwardly extending arm 131 of the member 61 secured to shaft 44. Itwill be recalled that the member 61 is normally urged in acounterclockwise direction (FIG. 14) by the spring 63. As so urged thearm 131 forces the rod 129 toward the right and by virtue of the collar130 serves to rock the member 127 in a counterclockwise direction. Tniscauses lifting of the rod 126 and pin 125 to raise the element 123sufiiciently to overcome any force 'of the spring 122 tending to urgethe disks 124 into tension applying relation to the thread. However,when the shaft 44 is rocked in a clockwise direction by the action ofthe knee press, in the manner described, the arm 131 will be drawn awayfrom the end of the pin 129'so that the rod 126 will be permitted todrop by gravity, and initially under the force of the spring 122.Movement of the rod 129 toward the left is limited by a collar 132secured thereto which cooperates with an arm of the bracket 128.

It should be understood that the knee press is normally operated tobring about the results above described when the needle is retractedfrom the node of Work and is in substantially its leftmost position. Atthis time the thread tensioning device 115 will be inactive by virtue ofthe lifting of pin 117 by eccentric 118. The application 10 of therelatively strong tension to the thread by the nipper mechanism 116 atthis time enables the operator to break the thread over the edge of thelooper by simply removing the work from the machine by a snappingmovement of the hand.

It is believed that the mode of operation of the machine of the variousmechanisms embodied in the improved machine, and their cooperativerelationship, will be understood from the foregoing detailed descriptionof an illustrative embodiment of the invention. A compact arrangement ofthe various devices has been provided in a manner to insure reliableoperation thereof, with a minimum of effort being required on the partof the operator to lower the work support into a position to facilitatethe introduction and removal of work. Simple and reliable devices areprovided for predetermining whether the machine is to produce a non-skipstitch or a skip type stitch and also to regulate the depth below thetop of the node former at which the curved needle passes through thenode of work. A highly desirable control over the tension on the needlethread is provided in a very simple and effective manner. This is suchthat during the normal operation of the machine, tension will be appliedto the needle thread during a certain portion of a cycle and will bereleased during another portion of the cycle, such release taking placeduring the time that the needle is retnacted from the work and is nearits extreme leftmost position, thus avoiding danger of breakage of thethread as the looper carries a seized loop of the thread from the rightside over to the left side of the node former. To facilitate severing ofthe thread after completion of the desired seam, the lowering of thework support by the operation af a knee press, or the like, serves toapply a nipping action to the needle thread so that it may be readilysnapped over the looper as the work is removed from the machine. 1

While a preferred embodiment of the invention has been described inconsiderable detail, it will be understood that various modificationsmay be made in certain portions of the mechanism within the scope of theappended claims.

What is claimed is:

1. In a blindstitch sewing machinehaving a frame, a rotary drive shaftjourna-led in said frame, and means for advancing work from the fronttoward the rear of said frame, the combination which comprises a worksupporting member along which the work to be stitched is advanced, saidwork support being pivotally connected with said frame for rockingmovements about an axis extending transversely of the direction of feedof the work, said axis being disposed adjacent the rearward end of saidwork support as viewed in the direction of feed of the work, cylindricalmeans cooperating with said work support to provide said axis, pivotmeans on said frame of the machine cooperating with said cylindricalmeans eccentrically of said axis, a node former rockably mounted on anaxis which is in fixed relation to said work support and positionedforwardly of the axis about which said work support is rocked,connections from said drive shaft to said work support for rocking thelatter about said first-mentioned axis to produce skip stitches and asingle means operable at will for turning said cylindrical means aboutsaid pivot means to cause lowering of said first mentioned axis and forrocking said work support about said first mentioned axis to therebyfacilitate the introduction and removal of work.

2. In a blindstitch sewing machine of the character set forth in claim1, a movable member carried by said frame, said connections from thedrive shaft to said work support including a toggle mechanism connectingthe forward portion of said work support with said movable membercarriedby said frame, and connections from said movable member carried by saidframe to said drive shaft for enabling the latter to operate said togglemechanism to rock said work support about its axis.

operable at will being adapted to turn said eccentrically mountedshaft-t vary the location of theaxis thereof.

4. In a blindstitch sewing machine of the character set forth in claim2, adjustable means in said connections from said movable member carriedby said frame to said drive shaft for varying'the normal position of 7said work support.

In, a blindstitch sewing machine of the character set forth in claim 2,connections from said means operable at will to said toggle mechanismfor rocking said work support downwardly about its axis.

6. In a blindstitch sewing machine having a frame, a rotary drive shaftjournaled in said frame, and means for advancing work from the fronttoward the rear of the frame, the combination which comprises a Worksupporting member along which the work to be stitched is advanced, saidwork supporting member being pivotally connected with said frame forrocking movements about an axis extending transversely of the directionof feed of the work, said axis being disposed adjacent the rearward endof said work support as viewed in the direction of feed of the work, anode former rockably mounted on an axis which is in fixed relation tosaid work support and positioned forwardly of the axis about whichsaidwork support is rocked, connections from said drive shaft to said worksupport for rocking the latter about said first mentioned axis toprovide skip stitches, means operable at will for rocking said worksupport about said first mentioned axis to facilitate the introductionand removal of work, said connections from said drive shaft to said Worksupport comprising a rock member and a toggle mechanism connecting saidrock member with said work support, and means operated by said meansoperable at will for operating said toggle mechanism to cause downwardmovement of said work support.

7. In a blindstitch sewing machine of the character set forth in claim6, said connections from said drive shaft to said work supportcomprising a second rock memberand a link connecting the latter withsaid firstmentioned rock member, and readily adjustable means forshifting the axis about which said second rock member is rocked tothereby determine the normal position of said work support.

. 8. In a blindstitch sewing machine of the character set forth in claim7, said connections from said drive shaft to said work support includingan eccentrically mounted disc and connections from the drive shaft for vrotating said disc, means carried by said second rock member in spacedrelation to the axis about which said member rocks, said last mentionedmeans cooperating.

with said eocentrical ly mounted disk for rocking of said second rockmember, a detaining member adjacent said disk adapted to cooperate withsaid last recited means to holdthe same out of engagement with said diskto thereby retain said second rock member against rocking movements, andreadily adjustable means for shifting said detaining member into and outof its operative position.

9. In a blindstitch sewing machine of the character set forth in claim8,.said detaining member being a substantially cylindrical elementmounted for turning movement about the axis around which said disk isrotated, said element having a depression in its peripheral surfaceadapted to be positioned directly opposite said means carried by saidsecond rock member when said element is turned into one position by saidlast recited readily adjustable means, to thereby enable said disk torock said second rock member. I

10. In a blindstitch sewing machine of the character setforth in claim9, said last recited adjustable means comprising a lever pivotallymounted on said frame and frame, and means connecting the opposite endof said lever with said element for turning the latter.

1 1. In a blindstitch sewing machine of the character set forth in claim8, spring means for urging said second rock member in a direction tohold said means carried thereby against a selected one of said disk andsaid detainer member.

12. In a blindstitch sewing machine of the character set forth in claim2, said axis about which said work support is adapted to rock beingprovided by an eccentrically mounted shaft, a collar secured to saidlast mentioned shaft, said toggle mechanism comprising a pair ofpivotally connected members one of which has its free end connected withthe work support and the other of which has its free end connected withsaid movable member carried by said frame, a link connecting the pivotof said toggle mechanism with a portion of said collar spaced from theaxis of said last recited shaft, spring means connected with said lastrecited shaft urging the latter to turn in a direction which will causesaid link to urge said toggle mechanism toward a straightened position,and means for limiting the extent to which said toggle mechanism may bestraightened.

13. In a blindstitch sewing machine of the character set forth in claim6, spring means for urging said means operable at will into an inactiveposition in which said means operated thereby is moved into a positionspaced from said toggle mechanism.

14. In a blindstitch sewing machine of the character set forth in claim3, spring means connected with said eccentrical ly mounted shaft forturning the same in a direction opposite to that in which it is turnedby said means operable at will andfor normally retaining this shaft in apredetermined angular position, a thread nipper mechanism carried by theframe of the machine, means secured to said eccentrically mounted shaftfor rendering said nipper mechanism ineffective when said eccentric-allymounted shaft is in its normal'position, and means for rendering saidnipper mechanism effective when said eccentrically mounted shaft isturned by said means operable at will.

l5.'In a blindstitch sewing machine of the character set fonth in claim1-, a rock shaft upon which said work support is mounted for saidrocking movements, spring means for turning said rock shaft and forrocking said work support in a direction opposite to that in which saidwork support is rocked by said means operable at will and for normallyretaining the rock shaft in a predetermined angular position, a threadnipper mecharism carried by the frame of the machine, means secured tosaid rock shaft for rendering said nipper mechanism ineffective whensaid rock shaft is in its normal position, and means for rendering saidnipper mechanism effective when said rock shaft is turned by said meansoperable at will. 16. In a blindstitch sewing machine having a frame, arotary drive shaft journaled in said frame, and means for advancing workfrom the front toward the rear of said frame, the combination whichcomprises a work supporting member along which the work to be stitchedis advanced, said work supporting member being pivotally connected withsaid frame for rocking movements about an axis extending transversely ofthe direction of feed of the work, cylindrical means cooperating withsaid work support to provide said axis, pivot means on said frame of themachine cooperating with said cylindrical means eccentrically of saidaxis, a node former rock-ably mounted on an axis which is in fixedrelation to said work support and parallel with and spaced horizontallyfrom the axis about which said work support is rocked, connections fromsaid drive shaft to said work support for rocking thelatter about saidfirst-mentioned axis to produce skip stitches, means operable at willfor rocking said work support about said axis to facilitate theintroduction a rotary drive shaft journaled in said frame, and meansforadvancing work from the front toward the rear of said frame, thecombination which comprises a work supporting member along which thework to be stitched is advanced, saidwork supporting member beingpivotally connected with said frame for rocking movements about an axisextending transversely of the direction of feed of the work, cylindricalmeans cooperating with said work support to provide said axis, pivotmeans on said fname of the machine cooperating with said cylindricalmeans eccentrically of said axis, a node former rockably mounted on anaxis which is in fixed relation to said work support and parallel withand spaced horizontally from the axis about which said work support isrocked, connections from said drive shafit to said work support forrocking the latter about said first-mentioned axis to produce skipstitches, and a single means operable at will for turning saidcylindrical means about said pivot means to cause the lowering of saidfirst mentioned axis and for 14 rocking said work support about saidfirst mentioned axis to thereby facilitate the introduction and removalof work, said connections from said drive shaft to said work support forrocking the latter comprising a rock member arranged to be rocked abouta predetermined axis, means carried by said rock member in spacedrelation to the axis about which it rocks, an :eccentrically mounteddisk adapted to be rotated, connections from said drive shaft to saiddisk for rotating the latter, said disk cooperating with saidlast-recited means to cause rocking of said rock member, a detainingmember adjacent said disk adapted to cooperate with said last-recitedmeans to hold the same out of engagement with said disk and therebyretain said rock member against rocking movements, and readilyadjustable means for shifting said detaining means into and out of itsoperative position.

References Cited in the file of this patent UNITED STATES PATENTS1,369,773 Bertrand Mar. 1, 1921 2,000,929 Dearborn May 14, 19352,129,402 Bowman Sept. 6, 1938 2,250,745 Buono July 29, 1941 2,280,468Bowman Apr. 21, 1942 2,678,619 Panry May 18, 1954

1. IN A BLINDSTITCH SEWING MACHINE HAVING A FRAME, A ROTARY DRIVE SHAFTJOURNALED IN SAID FRAME, AND MEANS FOR ADVANCING WORK FROM THE FRONTTOWARD THE REAR OF SAID FRAME, THE COMBINATION WHICH COMPRISES A WORKSUPPORTING MEMBER ALONG WHICH THE WORK TO BE STITCHED IS ADVANCED, SAIDWORK SUPPORT BEING PIVOTALLY CONNECTED WITH SAID FRAME FOR ROCKINGMOVEMENTS ABOUT AN AXIS EXTENDING TRANSVERSELY OF THE DIRECTION OF FEEDOF THE WORK, SAID AXIS BEING DISPOSED ADJACENT THE REARWARD END OF SAIDWORK SUPPORT AS VIEWED IN THE DIRECTION OF FEED OF THE WORK, CYLINDRICALMEANS COOPERATING WITH SAID WORK SUPPORT TO PROVIDE SAID AXIS, PIVOTMEANS ON SAID FRAME OF THE MACHINE COOPERATING WITH SAID CYLINDRICALMEANS ECCENTRICALLY OF SAID AXIS, A NODE FORMER ROCKABLY MOUNTED ON ANAXIS WHICH IS FIXED RELATION TO SAID WORK SUPPORT AND POSITIONEDFORWARDLY OF THE AXIS ABOUT WHICH SAID WORK SUPPORT IS ROCKED,CONNECTIONS FROM SAID DRIVE SHAFT TO SAID WORK SUPPORT FOR ROCKING THELATTER ABOUT SAID FIRST-MENTIONED AXIS TO PRODUCE SKIP STITCHES AND ASINGLE MEANS OPERABLE AT WILL FOR TURNING SAID CYLINDRICAL MEANS ABOUTSAID PIVOT MEANS TO CAUSE LOWERING OF SAID FIRST MENTIONED AXIS AND FORROCKING SAID WORK SUPPORT ABOUT SAID FIRST MENTIONED AXIS TO THEREBYFACILITATE THE INTRODUCTION AND REMOVAL OF WORK.